Mill-tube.



J. E. MILLER.

MILL TUBE.

APPLICATION FILED MAR. 18 1914.

1,162,502. Patented Nov. 30, 1915.

I u 1%} Q l l. I x I I l Mm lil H JESSE E. MILLER, OF KNOXVILLE, TENNESSEE.

MILL-TUBE.

Application filed March 18, 1914.

To all whom it may concern Be it known that I, JEssE E. MILLER, a citizen of the United States, residing at Knoxville, in the county of Knox and State of Tennessee, have invented a new and useful Improvement in Hill-Tubes, of which the following is a specification, reference bein had to the accompanying drawing.

I Iy invention relates particularly to such tubes as are used in flour mills forconducting the materials, in various stages of the operation, downward by gravity, and the object of the improvement is to form such tubes of sheet metal with suitable ports for the inspection of the material passing downward through the tube and for the admission of means for dislodging the material when the latter becomes clogged. Heretofore, such conducting tubes have in nearly all cases been made of wood and of rectangular cross-section. It is essential that such tubes be dust tight at all points, in order that no portion of the material passing through the tubes may escape into the mill. Such escape would be objectionable on account of loss of material and also on account of fogging the air in the mill. Making such wooden tubes dust tight is diflicult. It requires high mechanical skill, and only two or three varieties of wood are regarded as suitable for this purpose in this country, and these varieties are expensive. Hence these wooden tubes are objectionable on account of expensive material and expensive labor. They are further objectionable because they are combustible.

In view of the foregoing, eflorts have been made to substitute metal tubes for such wooden tubes; but this has been found to be a difficult task. It would not be difficult to make such tubing, if the inspection ports were not needed. But to apply such inspection'ports in suitable form to the metal P'bing is ditlicult. They must be dust tight and they must be of such shape as not to interfere with the flow of material and they must be of suitable size to admit long strips of wood or other devices used for dislodging the material in distant portions of the tube when there is clogging. The port must be free from angles or sharp edges which will interfere with the insertion of such a dislodging device or the insertion of the hand either up or down the tube. Furthermore, the devices surrounding the port and forming its closing means must be durable and inexpensive.

Specification of Letters Patent.

Patented Nov. 30, 1915. Serial No. 825,592.

In the ordinary flouring mill large numbers of such tubes are used and the total number of such ports is large, and if the construction is expensive the aggregate cost burden becomes excessive. Furthermore, the operation of opening and closing the port must be easy and simple.

In the accompanying drawings, Figure 1 s an elevation of a piece of sheet metal tubing embodying my improvement; Fig. 2 is a section on the line, 22, of Fig. 1; Fig. 3 1s a section on the line, 3-3, of Fig. 1.

Referring to said drawings, 1, 1, are cylindrical portions and 3, 3, are flat portions of a sheet metal tube. For the forming of said piece of tubing, a single rectangular piece of sheet metal is slitted at two places from each side edge toward the opposite edge far enough to leave between ends of opposite slits, 2, as much of the sheet as will form one-half the circumference of the tube. The parts, 3, of the sheet between the slits, 2, at the same edge of the sheet are left flat and straight and form walls which are parallel to each other. The remainder of the sheet is turned to cylindrical form, the meeting edges being suitably joined, as by overlapping and soldering.

The ends of the side pieces or walls, 3, are joined by sheet metal end pieces or walls, 4-, extending transversely to the length of the tube from one side piece to the other and having an outer straight edge meeting the side edges of the side walls and having an inner edge formed on a semi-circle to conform to the surface of the cylindrical portion of the tube and having a flange, 5, parallel to and resting upon the wall of the cylindrical portion, 1, said flange being soldered or riveted to the portion, 1. Each such end piece also has a flange, 6, directed toward the other end piece and lying against or over-lapping the adjacent side wall and being well secured thereto, as by means of sclder. Into the rectangular space inclosed by said side pieces, 3, 3, and end pieces, l, 4:, is placed a rectangular door wall, 7, the ends of which fit closely against the inner faces of the end pieces, at. Said door wall is preferably made of wood and of suitable thickness to make a support for the door, 8; but said door wall should not extend inward beyond the cylindrical portions, 1, of the tube; for if any portion of the accessories to the port projects into the tube such portion will hinder the flow of the material. The door wall is suitably secured to the side walls, 3, and end walls, 4, as by means of small nails.

In the door wall is a rectangular opening which forms an inspection port. The sides of said opening are shown parallel to the side walls, 3, while the upper and lower faces upper and lower ends being slanted to fit the slanting faces of the corresponding ends of the opening in the door wall, 7. A flange, 11, extends around the door and bears upon the outer face of the door wall, 7. A layer, 12, of felt or similar soft material is applied to the inner face of said flange or rim so as to bear upon the outer face of the door wall, 7, and prevent the passage of air and dust. On account of the slant of the lower face of the opening in the door wall, 7, and the corresponding slant in the opposite direction of the lower edge of the door to form a lip, 13, the door is to be inserted by leaning the upper portion outward and putting the lower portion thereof into place upon the lower face, 9, of the opening of the, door wall, 7, and then moving the upper portion of the door inward until all of the flange of the door bears firmly against the outer face of the door wall. The more the upper portion of the door is pressed inward, the more the lower portion will be forced inward on account of the pressure of the slanting face, 9, and the lip, 13, of the door upon each other.

When the door has thus been put into position, it may be held by a single securing device applied to the upper end of the door. For this purpose, the drawings show a button, 14, having a base, 15, and a raised finger, 16, bearing upon the outer face of the door. A screw, 17, extends downward through the base, 15, of the button and into the wooden door wall, 7. Said screw forms a journal upon which the button turns. By turning said screw inward or outward, the pressure of the finger of the button upon the outer face of the door piece may be varied.

Then the interior of the tube is to be inspected, the button is turned to free it from the door. The latter is then removed by first drawing its upper portion outward. Then the falling material can be observed. The hand of the attendant can be put through the inspection port, either up or down. The said port is surrounded entirely by corners or edges which do not injure the hand or arm of the attendant nor make scraping or cutting engagement with a strip or red inserted for removing clogged masses of material.

The construction described is simple and economical. The cutting of a metal sheet to form a tube section containing such an insertion port is simple, and the material used for the sheet metal end walls, at, for the wall, 7, and the door, 8, and the button, 14L, is inexpensive and easily formed. Such sections can be made in desired quantities and turned over to workmen to be combined with sections of sheet metal tubing of the same diameter and formed by methods employed in the manufacture of tubing used for stove-pipes, ventilating pipes, and downspouts for water, etc. The combination of these inspection port sections with such common sections of sheet metal tubing can be performed rapidly by persons of ordinary skill in sheet metal work.

The sheet metal of the tube needs reinforcing in some manner around the door opening in order to pr vide the required stability for a dust-tight seating for the door.

By making the door wall of wood, the inspection port becomes safer for the hands. It is desirable that sharp corners and edges be avoided. Furthermore, there is economy in the use of wood for this purpose. While it is expensive to provide the larger pieces of wood, of proper quality, for making the bodies of such tubing, the door wall may be made of waste pieces of wood which are produced as by-products of mill construction, so that in this case the Wood costs less than the sheet metal.

As to economy in the use of sheet metal for making the bodies of the tubes or spouts, it may be stated further, that, in practice, I have found a mill heretofore equipped with wooden spouts at a cost of about six thousand dollars can be equipped with my improved sheet-metal spouts for about fifteen hundred dollars, this economy being due to both material and labor. In addition to this advantage in economy, the sheet-metal tubes are fire-proof and, for a given capacity, occupy less space and for that reason permit denser grouping than is possible with the wooden tubes.

I claim as my invention.

1. In an apparatus of the nature described, the combination of a cylindrical sheet-metal tube, two fiat side walls parallel to each other and the length of the tube, a door wall between and supported by said walls outside the cylindrical body of the tube and having a door opening, a door fitting dust tight to said opening, and means for securing said door, substantially as described.

2. In an apparatus of the nature described, the combination of a cylindrical sheet-metal tube, two flat side walls parallel to each other and'the length of the tube, a

walls outside the cylindrical body of the tube and having a door opening, a flanged door fitting dust tight to said opening, and means for securing said door, substantially as described.

3. In an apparatus of the nature described, the combination of a cylindrical sheet-metal tube, two flat side walls parallel to each other and the length of the tube, end walls between said side walls, a door wall between and supported by said walls outside the cylindrical body of the tube and having a door opening, a door fitting dust tight to said opening, and means for securing said door, substantially as described.

4. In an apparatus of the nature described, the combination of a cylindrical sheet-metal tube, two flat side walls parallel to each other and the length of the tube, flanged end walls between said side walls, a door wall between and supported by said walls outside the cylindrical body of the tube and having a door opening, a door fitting dust tight to said opening, and means for securing said door, substantially as described.

5. In an apparatus of the nature described, the combination of a cylindrical sheet-metal tube, two flat side walls parallel to each other and the length of the tube, end walls having curved flanges fitting to the curved wall of the tube and flat flanges fitting to the faces of the side walls, a door wall between and supported by said walls outside the cylindrical body of the tube and having a door opening, a door fitting dust tight to said opening, and means for securing said door, substantially as described.

6. In an apparatus of the nature described, the combination of a cylindrical sheet-metal tube, two fiat side walls parallel to each other and the length of the tube, a door wall between and supported by said walls outside the cylindrical body of the tube and having a door opening in which is an inward slanting face, a door fitting dust tight to said opening and having a lip along one edge, and securing means adjacent the opposite edge of the door, substantially as described.

7. In an apparatus of the nature described, the combination of a cylindrical sheet-metal tube, two fiat side walls parallel to each other and the length of the tube, a door wall between and supported by said walls outside the cylindrical body of the tube and having a door opening in which is an inward slanting face, a flanged door fitting dust tight to said opening and having a lip along one edge, and securing means adjacent the opposite edge of the door, substantially as described.

8. In an apparatus of the nature described, the combination of a cylindrical sheet-metal tube, two fiat side walls integral with the tube body and parallel to each other and the length of the tube, a door wall located between and supported by said walls outside the cylindrical body of the tube and having a door opening, a door fitting dust tight to said opening, and means for securing said door, substantiallv as described.

9. In an apparatus of the nature described, the combination of a cylindrical sheet-metal tube provided with a reinforced door opening formed in part of two flat, sheet-metal side walls parallel to each other and the length of the tube, a door fitting dust tight to said opening, and means for securing said door, substantially as described.

In testimony whereof I have signed my name, in presence of two witnesses, this 6th day of March, in the year one thousand nine hundred and fourteen.

JESSE E. MILLER.

Witnesses:

W. J. FRASER, CYRUS KEHR.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents Washington, I). G. 

